Motor graders have a moldboard for moving earthen or other material. There are known motor graders that have a main frame, or chassis, to which a draft frame is attached via a ball-and-socket joint, a saddle frame attached to the main frame, a number of hydraulic cylinders (e.g., three) interconnecting the saddle frame and the draft frame for raising and lowering the sides of the draft frame and moving the draft frame side-to-side about the ball-and-socket joint, a circle frame rotatably attached to the draft frame, and a moldboard support having a tilt frame that is attached to the circle frame for rotation therewith and to which the moldboard is mounted. The tilt frame is pivoted to the circle frame to change the pitch of the moldboard in response to actuation of a hydraulic cylinder. A hydraulic sideshift cylinder interconnects the tilt frame and the moldboard and is operable to sideshift the moldboard relative to the moldboard support (i.e., to move the moldboard in translation relative to the moldboard support along a longitudinal axis of the moldboard).
There are known moldboards that have an upper sideshift rail and a lower sideshift rail. Each sideshift rail is in the form of a bar that is fixed to the back of a blade of the moldboard via a longitudinal channel to which the bar is welded and that is received by replaceable wear components, in the form of wear inserts, of two upper and two lower jaws of the moldboard support, mounted to the tilt frame, for sideshifting of the moldboard relative to the moldboard support in response to actuation by a moldboard-sideshift actuator in the form of a hydraulic cylinder.
Operationally, motor graders are versatile machines that are used to perform all sorts of tasks. Motor graders are often used for “rough grading” where the grader is used to move or level large quantities of material quickly. During the process of rough grading, the material will often spill over the top of the blade of the moldboard onto the bars and reside there. This material may include very abrasive particles, which can be ingested in between the wear components and the bars, resulting in rapid wear of the wear components and the bars when the moldboard is sideshifted. With such wear, the grip on the bars by the wear components loosens. This looseness resulting from wear in a rough grading operation as described here is not a hindrance to the performance of that particular operation, but it is unacceptable if the grader is then moved to a fine-grading task.
To eliminate looseness between the wear components and the bars, the upper jaws may be reconditioned by removing one or more shims in order to tighten the grip of the wear components on the bars or by replacing the wear components. Over time, wear on the bars themselves becomes excessive, and the ability to tighten the grip of the wear components by adjusting or replacing the wear components is no longer effective. Solutions to this issue have included removing and replacing the entire moldboard (after which the worn moldboard is sometimes scrapped altogether or relegated to some other old grader that does no finish work), or removing and replacing just the worn bar, both of which have drawbacks (e.g., cost, inconvenience, and operational downtime).